We see the impossible waterfall construction as Penrose tribar on both images. Water raises up by the sloping sides of the triange and falls along the vertical side.
Artist's deviantART profile http://deadyeti.deviantart.com
Artist also created a desktop wallpaper. You can see small size image of the wallpaper below and download it from http://deadyeti.deviantart.com/art/Water-Feature-Final-116740943.